var RequestAnimationFrame = require('../dom/RequestAnimationFrame'); 
var MainLoop = function (game, framerate){ 
this.game = game; 
this.raf = new RequestAnimationFrame(); 
this.timestep = 1000 / framerate; 
this.physicsStep = 1 / framerate; 
this.frameDelta = 0; 
this.discardedTime = 0; 
this.lastFrameTimeMs = 0; 
this.fps = 60; 
this.lastFpsUpdate = 0; 
this.framesThisSecond = 0; 
this.numUpdateSteps = 0; 
this.minFrameDelay = 0; 
this.running = false ; 
this.started = false ; 
this.panic = false ; 
} 
; 
MainLoop.prototype.constructor = MainLoop; 
MainLoop.prototype = { 
setMaxFPS: function (fps){ 
if (fps === 0) { 
this.stop(); 
} 
 else { 
this.minFrameDelay = 1000 / fps; 
} 
} 
,
getMaxFPS: function (){ 
return 1000 / this.minFrameDelay; 
} 
,
resetFrameDelta: function (){ 
var oldFrameDelta = this.frameDelta; 
this.frameDelta = 0; 
return oldFrameDelta; 
} 
,
start: function (){ 
if (this.started) { 
return this; 
} 
this.started = true ; 
this.running = true ; 
this.lastFrameTimeMs = window.performance.now(); 
this.lastFpsUpdate = window.performance.now(); 
this.framesThisSecond = 0; 
this.raf.start(this.step.bind(this), this.game.config.forceSetTimeOut); 
} 
,
step: function (timestamp){ 
var active = this.game.state.active; 
var renderer = this.game.renderer; 
var len = _AN_Read_length('length', active); 
if (len === 0 || timestamp < this.lastFrameTimeMs + this.minFrameDelay) { 
return ; 
} 
this.frameDelta += timestamp - this.lastFrameTimeMs; 
this.lastFrameTimeMs = timestamp; 
this.game.input.update(timestamp, this.frameDelta); 
for (var i = 0; 
i < len; i++ ){ 
active[i].state.sys.begin(timestamp, this.frameDelta); 
} 
if (timestamp > this.lastFpsUpdate + 1000) { 
this.fps = 0.25 * this.framesThisSecond + 0.75 * this.fps; 
this.lastFpsUpdate = timestamp; 
this.framesThisSecond = 0; 
} 
this.framesThisSecond++ ; 
this.numUpdateSteps = 0; 
while (this.frameDelta >= this.timestep){ 
for (i = 0; i < len; i++ ){ 
active[i].state.sys.update(this.timestep, this.physicsStep); 
} 
this.frameDelta -= this.timestep; 
if (++this.numUpdateSteps >= 240) { 
this.panic = true ; 
break ; 
} 
} 
var interpolation = this.frameDelta / this.timestep; 
renderer.preRender(); 
for (i = 0; i < _AN_Read_length('length', active); i++ ){ 
active[i].state.sys.render(interpolation, renderer); 
} 
renderer.postRender(); 
if (this.panic) { 
this.discardedTime = Math.round(this.resetFrameDelta()); 
} 
this.panic = false ; 
} 
,
stop: function (){ 
this.running = false ; 
this.started = false ; 
return this; 
} 
}
; 
module.exports = MainLoop;